1. Field of the Invention
The present invention relates to a golf ball which exhibits an excellent controllability, shot feeling, durability and flight distance.
2. Description of the Related Art
As conventional golf ball, a wound-core golf ball with a Balata rubber cover and a multi-piece golf ball with an ionomer resin cover are well-known. The wound-core golf ball with a Balata rubber cover is widely used by high-level amateur golfers and professional golfers, because they have superior shot feeling and controllability. However, the golf ball with a balata rubber cover is expensive because of a complicated process, and the golf ball has a problem of a durability and cut resistance. The multi-piece golf ball with an ionomer cover is also widely used, because of good durability and fright performance. But it has been pointed out that the shot feeling and controllability of the golf ball with ionomer cover is inferior to the golf ball with Balata rubber cover.
In view of the foregoing circumstances, it is desired that the golf ball exhibits the feel and control which the Balata rubber cover imparts as well as the durability and flight performance which the ionomer cover does. For example, Japanese unexamined patent publication No. 2002-102390 discloses the golf ball excellent in repulsion property (flight performance), durability and spin rate (controllability). The golf ball is characterized in that the cover satisfies the specific relationship between stiffness modulus and Shore D hardness by containing an organic fiber in covering material including thermoplastic resin or a thermoplastic elastomer.
Further, Japanese Patent No. 2662909 proposes a golf ball with a polyurethane cover which is excellent in durability, repulsion property and controllability.
In the golf ball disclosed in Japanese unexamined patent publication No. 2002-102390, the organic fiber is contained in the cover material including a thermoplastic resin or a thermoplastic elastomer. Use of the organic fiber causes to lower repulsion property and flight performance. And, Japanese patent No. 2662909 has disclosed a golf ball which has a polyurethane cover formed by curing a urethane prepolymer with a slow-reactive polyamine curing agent. However, the golf ball with a resultant polyurethane cover is not satisfactory in term of flight performance.